I Need Help! How do you wire an MTH Railking O Scale 7 Light Signal Block #30-11013 with Isolated Rail and/or Relay, Not with an ITAD?

Here's one way using an Azatrax relay.

Where to connect the Blue wire depends on what you want the lone single-lamp to do.  I recall one guy on OGR wanted to make this lamp flash and we worked out a way to do that - it had nothing to do with what is/was prototypical.

Thank you stan2004, I'll probably just hook the blue wire to the accessory hot wire so it lights all the time and have the relay change the light pattern. I knew it was probably something quite simple but I just couldn't figure it out. It's been a long time since I've worked with relays. I'm using Fastrack and know how to do the insulated rail. Thanks again!

Stan2004,

Will that Azatrak relay work for a 3 over 3 block signal, MTH 30-11024?  It has 2 separate signals and I'm triggering it green to red when a car comes into an isolated track section (2 separate isolated sections).

Also, I want a timer so it stays red for perhaps 5 seconds (eliminate chatter) because I have some short isolated sections and some wheels might get dirty and provide intermittent contact.

Z-4000 using 14V fixed, DCS, Atlas O 3-rail track

For what it's worth, a PRR signal displaying 3 horizontal lights means STOP.  A signal displaying 3 horizontal lights with a single light below them means STOP AND PROCEED.  A train approaching a STOP AND PROCEED signal should stop, then proceed at restricted speed (20 mph or less).  A STOP signal is like a red traffic light: stop and wait until it changes, whereas a STOP AND PROCEED signal is like a stop sign.

@SteveG posted:

...

Will that Azatrak relay work for a 3 over 3 block signal, MTH 30-11024?  It has 2 separate signals and I'm triggering it green to red when a car comes into an isolated track section (2 separate isolated sections).

Also, I want a timer so it stays red for perhaps 5 seconds (eliminate chatter) because I have some short isolated sections and some wheels might get dirty and provide intermittent contact.

The Azatrax relay will work.  Like you say, the MTH 30-11024 is 2 separate signals so you'd need two relays...one controlling each signal.  But the relay is "just" a relay and does not have a built-in timer to suppress chatter from intermittent contact from dirty wheels/track.

3 options come to mind:

1) GRJ's Insulated Track Signal Driver (ITSD) available from Hennings Trains.  This essentially functions like the Azatrax relay but you can add a ~50 cent capacitor to effect a time delay.  It is apparently $27 MSRP.  This was designed-built for the train market and you can read more than you could ever want to know about it in this 5 year old OGR thread.

2) A generic (i.e., not designed for the train market) relay module that has time-delay capability.  There are MANY of these widgets out there.  Here's one that I use myself and have recommended on OGR for various and sundry applications.  These modules are about $5 each.  You need to fuss a bit to "program" them using the buttons on the bottom of the module.  They are remarkably capable widgets allowing you to set the time delay to exactly 5.0 seconds (if that's what you want), or 5.1 sec or 4.9 sec, etc.  These modules require DC voltage to operate, but this DC voltage can come from just about any DC-output adapter (aka wall-wart) you probably have lying around in the attic/garage.

3) A generic relay module that does is "just" a relay like the Azatrax.  Then add some components to effect a timer delay for the application at hand.  I have also recommended and shown how to do this in many OGR threads.  Generic relay modules are about $1-2 per relay and come in various configurations such as 1, 2, 4, 8, etc. relays.  Here's a photo I dug up from a previous OGR thread that shows a 4-relay module with a few components added to effect timer delay for relay chatter suppression on the lower 2 channels.  The components are inexpensive- maybe 50 cents to $1 per channel - but obviously requires fussing at the component-level (resistors, capacitors, etc.).   Like option 2) these inexpensive relay modules operate on DC voltage.

You will be able to get help with all 3 options here on OGR.  And I'm sure there are other Options too.

Thanks for the informative reply!

For another 30-11024 block signal I've never used I'm going to look for the timer with relay in option 2 as it seems a simple and cost effective solution.  I have a 12V DC adapter that I will use as the power source.

For my existing block signal I have an old Radio Shack 275-206 relay (12V DC, 3 A, I believe 160 ohms) and a full  wave bridge rectifier with the + of rectifier going to + coil of relay and - of rectifier going to - coil of relay.  The signals do work correctly.

The problem is I get chatter if the wheels are even slightly dirty.  I have a 1000 MFD 35V capacitor across the relay coil with - to  -, + to + but I get no delay in signal changing and I get the chatter.  I already had this setup in a previous layout several years ago and it worked fine, so I'm wondering why the chatter is there.

I also added 33 ohm 1 W resistor to the wire going to isolated track which I've seen in several threads for this arrangement to eliminate sparks on the wheels.  Did not add a diode, but I have some available if needed.

I tested capacitor by having it on the relay coil when signal is activated with train on the isolated track, then removing it and the voltmeter reading on capacitor for DC is 10.70 volts and declines slightly every second (10.69, 10.68, etc.).

seems to be a good capacitor.

@SteveG posted:

Thanks for the informative reply!

For another 30-11024 block signal I've never used I'm going to look for the timer with relay in option 2 as it seems a simple and cost effective solution.  I have a 12V DC adapter that I will use as the power source.

For my existing block signal I have an old Radio Shack 275-206 relay (12V DC, 3 A, I believe 160 ohms) and a full  wave bridge rectifier with the + of rectifier going to + coil of relay and - of rectifier going to - coil of relay.  The signals do work correctly.

The problem is I get chatter if the wheels are even slightly dirty.  I have a 1000 MFD 35V capacitor across the relay coil with - to  -, + to + but I get no delay in signal changing and I get the chatter.  I already had this setup in a previous layout several years ago and it worked fine, so I'm wondering why the chatter is there.

I also added 33 ohm 1 W resistor to the wire going to isolated track which I've seen in several threads for this arrangement to eliminate sparks on the wheels.  Did not add a diode, but I have some available if needed.

OK, so I'll do the math here in "real time" not knowing the answer!

A 1000uF capacitor charged to 10.7V has 1/2 * C * V * V = 0.06 Watt-seconds (Joules) of energy stored.  If your 12V relay coil is indeed 160 Ohms, that suggests the coil power is V * V / R = 0.9 Watts.  That means, ignoring the geeky physics of how capacitors discharge, your capacitor can "power" the relay coil for at most 0.06 Watt-sec / 0.9 Watts = 0.07 seconds.  0.07 seconds is not even a tenth of a second so I can see how that would not be enough to cover for dirty/intermittent wheel-track contact.  I like to budget 1/4 second (or more) of time for wheel/track chatter suppression so the signal head does not flicker red-green-red-green.  Your mileage may vary!

If you're game to try the timer I show, I know exactly how to program it for what you want.  It has a plethora/multitude of timing modes; you want "mode P1.2" which I realize makes no sense until you read the instructions.  Then set the time delay to 5.0 seconds or whatever (I'd think you want something shorter like, say, 1.0 seconds but whatever works for you). It appears like you know your way around wiring and such but I can draw you an exact wiring diagram if that helps.

The timer is widely available on eBay, Amazon, and so on.  You can save a few bucks if you don't mind waiting for shipping from Asia (2-3 weeks).

As to Option 3, for those wanting to save yet a few more bucks, the "trick" with the low-cost eBay/Amazon relay modules is the trigger input does not directly drive the relay coil like your bare-bones Radio Shack relay.  There is a transistor amplifier/buffer which reduces the trigger power by at least a factor of 10.  So in an apples-to-apples comparison, that same 1000uF cap that only kept your Radio Shack relay going for less than a tenth of a second would keep it going for over a second.  Again, this method requires fussing at the component-level and there are i's to dot and t's to cross but if inquiring minds want to know I can dig up some relevant OGR thread(s). 

Stan2004,

I thought the 1,000 uF capacitor was too small because I have a much larger one on a crossing gate that I used in an old layout (not installed yet on new layout), so I bought two 22,000 uF capacitors with the old RS relay and bridge rectifier and they work great!  No chatter!  I get about a 4 second timer with them and that's just fine.

For the new block signal not yet installed, I went ahead with your suggestion and bought two of these.  They look just the same as what you posted.  couldn't get it cheaper.  most of the search results on ebay have two connectors on one side, not the three you posted, and it was the best I could do after bargaining. Not a big deal.  Once they come in, which will be weeks from now,  I will post here and ask for your help with the timer piece if I need it (I will probably will!).

appreciate your time helping out

I cobbled together a proof-of-concept using the 6-30V timer relay module.

The white section of track is the insulated-rail trigger zone.  The timer module is powered by 12V DC coming from the left.  I used a pair of 14V bulbs to simulate your 3-wire signal head(s).  The timer module is set to mode P1.2 as discussed earlier.  In this case I used a delay time of 4.0 second though it can be set to anything you want.

Note that I modified the diagram using this timer module to use a diode; you mentioned you have diodes in your "stash."  One diode can handle two (or more) modules.

---

Separately.  Yes, the math works for your 22,000uF cap method.  That's 22x the energy storage of a 1000uF cap so should yield a delay of several seconds which is apparently what you get!  Amazing.

I see I did not identify the inexpensive 6-30V relay timer module example as being from Aliexpress.com.  2 modules for ~$6 shipped...but means a "new" vendor so unclear if worth the bother to save a couple bucks if you're already set up on eBay.  I've recently started using Aliexpress  (Asia) and have had no problems getting electronic components and modules so far with shipping time about the same (2-3 weeks) as from eBay-Asia sellers.

Thanks.  Relay with timer Just arrived surprisingly fast.  On the left side from top to bottom I have 6-30V IN for the DC source +, GND for the DC source -, then Trigger, then GND-T.

It seems from your diagram which I have copied here, the trigger is my 14V fixed AC from Z4000, then diode which I have.

The GND-T appears to be the wire from isolated track.  Is that correct?  In your POC it looks like you have the diode between trigger and common on other side.

The diagram is correct.

Trigger+ is from the diode (side with the band). Trigger- is from isolated track.

Yeah, I see now the video can be confusing since the trigger- wire is orange which does not match diagram (blue). And it just happened the 14v ac in video came from right side and I just happened to wire in diode on right side. But the band side of diode is on the left in video and then goes to trigger+ with white wire. Sorry about that!

Possibly too-much-info but one thing I like about this particular timer relay module is that it has an electrically isolated trigger input. Hence it requires 2 trigger wires, a + and a -. They chose GND-T to label the trigger- which is potentially confusing. But that's a separate discussion we can have (or not) after you are up and running. ☺

Doing quick connections to test it, the led blinks at P1.1 and I have a steady green on the signal even if I apply trigger voltage by having a car enter the isolated track.

There are no instructions.  If I press UP, thinking it would move up to P1.2, LED continues to blink P1.1.

could it be it has to be program for the trigger to activate and turn signal red?

The instructions are in the eBay listing itself.  Here's the words pasted from the listing # you referenced:

-----------

In your video it starts at P1.1 blinking and quickly goes to 000.

mine stays at blinking P1.1

i am asking the seller.

i get 11.3 v dc on input.

i wanted to use a wall adapter as the dc source that is supposed to give 12V / 2 A but when i put a voltmeter to the wires it jumps from 8 v dc to near 0 then up, down, keeps changing many times a second.  This doesn’t seem right, so I have a full wave bridge rectifier and powered it windows with the 14v fixed from Z4000.  Output is 11.3 v dc going to the dc+ and dc- terminals on left hand side.

I tried powering with the 14V AC from a Z4000 via a bridge rectifier.  The module never quite powers up and has all digits-segments on dimly.  But by placing a 1000uF capacitor with proper polarity on output of bridge rectifier the module powers up correctly flashing P1.2 about 3 times then goes to 000 ready for action.

That is, a bridge rectifier by itself generates choppy DC that I don't think the module likes.  The capacitor smooths it out.  I was reading about 16V DC at the module (with the 1000uF capacitor).  I used 1000uF because I believe you may have some lying around.

Your 12V 2A adapter definitely appears screwy if DC voltage is hopping around!

Thanks so much Stan.

Are you saying to place a capacitor across the DC output of the bridge rectifier like this?

Yes. So the 14v ac wires from z4000 red/blk go to the squiggly line  terminals of bridge. The + and - bridge outputs go to the + and - capacitor terminals respectively...and then onwards to the dc+ and dc- inputs of timer module.

Without the capacitor your DC meter will read about 11-12V. With the cap it will read about 16-17V. Note that timer module operates 6-30V so all's well.

Perfect!  You are Stan the Man.

The capacitor did the trick.

Appreciate the diagram and testing you did.  I just happen to have another Radio Shack FW bridge rectifier and 1000MFD capacitor for the other block signal (it's a 3-over-3, so two signal circuits are needed).  I bought a few more back in the day, probably 15-20 years ago, thinking I would use this other block signal on my old layout.  Never did.  It's a bit hard to fasten the wires into the screw terminals of the relay time module.  I might solder thicker gauge wire to the leads of the block signals so they fasten better to the screw terminals.

@SteveG posted:

... I just happen to have another Radio Shack FW bridge rectifier and 1000MFD capacitor for the other block signal (it's a 3-over-3, so two signal circuits are needed).

You should be able to use one FW bridge rectifier and 1000MFD capacitor to power two (or more) timer modules.  And as mentioned earlier you only need one diode from 14V AC hot to the trigger+ inputs of both (or more) timer modules.  In other words, the DC+, DC-, and trigger+ inputs to multiple timer modules can be tied together.  It's only the trigger- signal that must be independent/separate for each timer circuit.

But since you have extras of the relevant components, wiring logistics might make it easier to duplicate the external components.  Whatever works!

----

Separately I was reminiscing about going to the local RS.  I dug up my 20 year old RS paper catalog and found your 12V DC relay, and probably the FW bridge rectifier and 1000MFD caps you used.  Couldn't find a 22,000MFD capacitor (largest was 4700MFD) so presumably you got that elsewhere.  But it's interesting how many if not most OGR-type projects could be fulfilled by a small retail storefront with limited selection.   And a free battery too for card-carrying members!

yeah, that's it.  I'm using the 275-206 relay and the 276-1173 FW bridge rectifier.

Good to know about being able to use the diode and bridge rectifier on multiple circuits.  Will have to keep that in mind if I buy more of these signals.

The 22,000 MFD capacitors I bought from Digi-key recently.